I usually ride Tuesdays & Thursday after work to do a 25 miles ride. Lately it's been 85+ at 4:30 pm when I usually want to start my rides. I simply can't handle heat, even if I take a Camelback filled with ice. A lot of times on the hills there is a "dead air" spot that really takes it out of me. Any suggestions? I feel guilty not riding but I certainly don't want to get heat stroke either.